ARM: pxa: add clk support in gpio driver

Support clk in gpio driver. There's no gpio clock in PXA25x and PXA27x.
So use dummy clk instead. And move the gpio edge initialization into
gpio driver for arch-mmp.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>

arch/arm/mach-pxa/pxa27x.c

@@ -230,6 +230,7 @@ static struct clk_lookup pxa27x_clkregs[] = {
 	INIT_CLKREG(&clk_pxa27x_im, NULL, "IMCLK"),
 	INIT_CLKREG(&clk_pxa27x_memc, NULL, "MEMCLK"),
 	INIT_CLKREG(&clk_pxa27x_mem, "pxa2xx-pcmcia", NULL),
+	INIT_CLKREG(&clk_dummy, "pxa-gpio", NULL),
 };
 
 #ifdef CONFIG_PM